Artificial limb



March 12, 1935. I l. ALTERMAN 1,994,185

ARTIFICIAL LIMB Filed sept. 24; 1952 y ZM? :ff/701%# ys.

Patented MarQlZ, 1.935 n UNITED .stares cargar orifice ARTIFICIAL LIME Israel Alterman, Philadelphia, Pa., assigner tov William Hirsch, Philadelphia, Pa., 'as trustee Application September 24, 1932, Serial No. 634,627

1i claims. (c1. 3 2) This invention relates to artificial limbs and fairly fixed relationship to the upper portion of particularly to an improved limb in which the the body, the shin section has very substantial shin section may be secured against angular movements relative thereto. As a result of this movementrelative to the high section. `prior construction so much of the socket is taken 5 In an artificial limb it is required that Vfree up by the controlling elements that if amputation 5 movement of the shin section about its pivotal has taken place directly above the knee the socket connection with the thigh section take place in must be unnaturally elongated with the result order to permit sitting andA walking. It is dethat when the wearer occupies a sitting position sirable, however, that during walking' there the knee of the articial leg projects visibly for- .10 should be some provision made to swing the shin Wardly of the knee of the other leg. l0

section forwardly during the taking of steps so In accordance with the present invention, the as to simulate ordinary walking conditions and controlling mechanism, while necessarily conalso to move the foot suiciently forwardly to nected to the thigh section, is primarily contained take the weight of the body. In general, the ar- Within the shin section. The controlling cord rangement for throwing theshin forwardly is reor strap secured to Suspenders over the wearers l5 silient and does not resist to any great degree shoulders extends down the front of the thigh the attainment by the shin section of a position section and is guided about the knee portion substantially at right angles to the thigh section thereof into the shin section. The mechanism is when the wearer is seated. such that this arrangement can be provided One of the primary objections to artificial without any interference with the functions of 20 limbs of the type heretofore provided has been the controlling means irrespective of the position that if the shin section of the artificial limb is reof the shin section. tarded in its forward movement a buckling of One of the primary requirements for any conthe limb will take place at the knee joint with the trolling mechanism is, of course, lightness coupled result that the wearer will fall. Contact of the With compa/ctness. The arrangement of the 25 toot of the kartificial limb with any such object present invention satisfies all requirements of as a stone or curb, or the like, will produce this this character being very light in weight `and result. Obviously in such cases the wearer does concentrated at the extreme upper portion of the not have time to take anyprecautions against shinl member so that its effective movement of falling and consequently devices heretofore deinertia is minimum. Y 30 signed to prevent buckling of the limb have been Another object of the invention is the provision made to be rendered active by a v subconscious of a controlling mechanism which is readily acmovement, primarily the drawing rearwardly of cessible so that, if necessary, it may be removed the shoulders when the wearer is about to fall, lfor cleaning or replacement of parts.

which action is spontaneous and natural. In the The controlling mechanism forming the sub- 35 arrangements heretofore provided tov lock the two ject matter 0f the IlVeIltOn iS not Only 0f a' type sections of the limb together, when locking takes which is entirely satisfactory in cases where only place, freeing of the sections for a subsequent onearticial limb is worn but is also satisfactory step is difficult andV requires an unnatural operain Cases Where GWO artificial limbs are Worn yin tion. Furthermore, the devices do not permit of which case, as will be obvious, the provisions 40 the desirable action of throwing the shin section against buckling are DaTtCUlaIlY mpltant. The forwardly in taking astep. objects of the invention enumerated above to- It is the broad object of the present invention gether with other objects relating particularly t0 to provide an articial limb in which the parts details of construction will be apparent from the may be locked together to prevent buckling while following description read in conjunction with 45 at the same time there is no interference either the accompanying daWlg in WlflChll with the normal Swing of the Shin portion in Fig. 1 is a vertical sectional Aview through the walking or with the relative position of the two knee-joint of the improved artii'lcal limb, `the sections when the wearer assumes a sitting posection being taken at right angles to the pivotal sition. aXis; Y 50 Heretofore it has been customary to locate the Fig. 2 is a diagrammatic View illustrating the controlling elements for the shin within the lower positions ofthe parts when the wearer assumes portion of the thigh sectionY or socket. This, in -a sitting position; n fact, has been more or less assumed necessary Fig. 3 is a similar diagrammatic View illusinasmuch as while the thigh section occupies a trating the positions of the parts when the shin 55 and thigh sections are locked together to preends inserted within openings in screws 11 thread-A ed into the side walls of the shin section. "The member 8 is of course ixedwith respect to the shin in all of its positions and servesprimarily as a reinforcement and aback-stop by engagement with a pady 12 carried by the knee portion of the thigh section. The socket opening in the thigh section is defined in part by the curved surface 14 above which may be located a cushion indicated at 16 upon which the padded stump of the wearer may rest. As will be obvious from Fig. 1, the device is adaptable to. cases where amputation has occurred immediately above the knee inasmuch as the available opening in the socket extends substantially to the knee portion thereof. This may be contrasted with the usual arrangements in which controlling mechanism is located within the thigh section and requires a controlling strap extending outwardly through openings in the thigh section spaced substantially upwardly of the knee portion thereof.

Pivoted .on thepin 1() is a link 18 having xed in its rear end a pin 20 providing a pivot between the link 18 andthe lower portion 22 of a second link.Y This second link is a vcomposite one and is collapsible inasmuch as it consists of one part 22 providing a cylinder 24 in which there slides the second part consisting of a plunger 26 adjustably threaded upon a pin 28 pivoted on a transverse pin 30 carried by the thigh section.v A spring 32 reacts between adjustable nuts 33 and 34 carried by the pin 28 and cylinder 24 -respectively. The spring 32 is of compression type and tends normally'to expand the collapsible link.

A cord 36 is secured at its upper end to the lower portion of the plunger 26 from which it-extends downwardly passing about a pulley 38 carried by the part 22 of the collapsible link thence'through a ring 40 and about a pulley 42 mounted on the pin 20 and finally to a ring 44 carried bythe forwardly extending arm of the link 18 to which it is secured. The ring 40 which preferably car-f ries a small pulley to receive thecord 36 is secured to the lower end of a strap or cord 46 which is guided within a slot 48 in the knee portion-of the thigh section and thence-passes upwardly ito the front of the usual Suspenders carried on'the shoulders of the wearer, the rear vportions of which are secured to the rear of the top of the thigh section. A tension spring 50 which is normally loose when the parts are in the position illustrated in Fig. 1 is connected between the cord or strap 46 andthe forwardly extending arm of the link 18.

The member 8 is provided with a depression indicated at 52' with which may contact a cushion or plurality of cushions 54 mounted concentrically upon the pin 20. This, as will be obvious hereafter, limits the movements of the links.

'W hen the wearer-is walking in the normal-fashion and the shoulders are heldin normal position, the parts will occupysubstantially Tthe positions 'illustrated in Fig. 1. At this timethe-link "18 retains substantially the position illustrated relative to the shin irrespective of the position of thef shin relative to the thigh section. Flexure may take place in the ordinary walking movements by more or less compression of the spring 32 as will obviously be the result when the shin section pivots about 6 relatively to the thigh section and the link 18 remains substantially xed. The slack in the cord 36 occasioned'bythis movement makes. up for the fact that the strap K46Yis"sllbstantially xed about the knee portion of the thigh section.

A'The compression of the spring 32 when flexing of the knee joint takes place tends to throw the shin section forwardly during the forward step of the artificial limb. Accordingly the spring 32 acts to help walking.

When .the wearer moves to a sitting position the body is not usually held as erect as during walking. As a result, slack is given to the strap 46 and the spring 32 is free to expand due to the fact that the link 18 will pivot clockwise as viewed expansion of the spring takes place, the shin section is quite free to occupya position at a *right* angle to the thigh section as illustrated in Fig.f

2. When the wearer wishes to rise the shoulders'v are generally raised somewhat -so that thelink;

18 is pulled counterclockwise tensioning the spring 32 and thus aiding the rising laction as weight vis brought upon the articiallimb'. The mere act of rising, accordingly, brings therparts into normal position for walking.- l

The most important function of the improved arrangement is illustrated invFig. 3. If the wear- `er trips and is about to Yfall there is a tendency to throw the shoulders backwardly to'gain 4equi- 'in Figs. 1 and 2. Asa result, evenV though some librium. This causesv a pull upon therstrapf46 .Y

parts is just slightly short of the dead vcenter position so that, as will be obvious, a restoration of the parts to normal position is'readily effected.

When. the parts occupy theyposition illustrated in Fig. 3, it is not the force exerted by thes'houlders of the wearer which prevents buckling fbut rather the fact that'the two links inttheirsubstantiallyfdead center positions act effectively as a single -rod rigidly separating pivots 410land30.

While the illustration in Fig. 3 shows the shin and thigh sections substantially' in alignment `the adjustment of nuts 33 and 34 ispreferably such that at this time some furtherv slight' compression-of the spring 32 may take place. How.-

ever, thespring 32 will be fully compressedjwhen only a slight angularvdisplacement of -theshin relatively to the thigh occurs., It will be obvious that'substantially the same results-are produced with merely a slightly less approach to dead center position if the takeup on the strap 46'oc.

curs when there is evena substantial relative angularity between the shin and thigh sections.

During the action just illustrated the spring 50 is elongated. This spring is arranged to break the toggle to restore the Vparts to their normal a I l positions when the tension uponv the strapv46 is released. The spring, `it will be noted, not only pulls the strap 46 `downwardlybutv also tends'to swing the link 18 clockwise. I A

VFrom the above arrangement it will be-seen that there is provided a device in 'which with little elort and, in fact, subconsciouslyf on Vthe part of the wearer, the shin and lthigh sections are locked together` to preventV buckling. It will also be seen that restoration of l-the parts to normal walking position, Yeither from the sitting or locked position, takes place substantiallyv autoinatically.v In cases where very rigid locking is required, as where two artificial legs are worn, it maybe desirable to connect the strap 46 directly with the pin 20 or a `pin substantially at the position of the pulley 38. In this case, the plunger is left free but the full eiort exerted by the shoulders of the wearer is utilized to bring the two links into dead center position. Greater safety and prompter reaction to stumbling is thus elected.

It will b'e obvious that various changes may be made in the specic embodiment of the invention without departing from the spirit thereof as defined in the following claims.

What I claim and desire to protect by Letters Patent is: y

1. An artificial limb including pivotally connected shin and thigh sections, a linkage including a pair of members pivoted to each other and also to the shin and thigh sections respectively, Said linkage yielding by relative movements of the members about their pivotal junction under normal conditions thereby permitting pivoting of the shin section relatively to the thigh section, and means for preventing relative movements of the members vabout their pivotal junction to lock the shin section relatively to the thigh section, said last means acting by bringing said members approximately into a dead center condition.

2. An artificial limb including pivotally connected shin and thigh sections, a linkage including a pair of members pivoted to each other and also to the shin and thigh sections respectively, said linkage yielding by relative movements of the members about their pivotal junction under normal conditions thereby permitting. pivoting of the shin section relatively to the thigh section, and means for preventing relative movements of the members about their pivotal junction to lock the shin section relatively to the thigh-section, said last means acting by bringing said members approximately into a dead center condition, one of said members being collapsible between its pivots.

3. An artificial limb including pivotally connected shin and thigh sections, a linkage including a pair of links pivoted to each other and also to the shin and thigh sections respectively, said linkage yielding by relative movements oi the links about their pivotal junction under normal conditions thereby permitting pivoting of the shin section relatively to the thigh section, and means for preventing relative movements of the links about their pivotal junction to lock the shin section relatively to the thigh section, said last means acting by bringing said links approximately into a dead center condition, one of said links being collapsible, and comprising two relatively slidable parts and a spring urging them into extended condition.

4. An artificial limb including pivotally connected shin and thigh sections, a linkage including a pair of links pivoted to each other and also to the shin `and thigh sections respectively, one of said links being resiliently collapsible, said link being normally collapsed during pivotal movements of the shin section about the thigh section, and means controlled by the wearer for collapsing said link irrespective of suchpivotal movements.

5. An artificial limb including pivotally connected shin and thigh sections, a linkage including a pair of links pivoted to each other and also to the shin and thigh sections respectively, one oi said links being resiliently collapsible, said linkV being normally collapsed during pivotal movements of the shin section about the thigh section, and means controlled by the wearer for collapsing said link irrespective of such pivotal movements, said last means also serving to ro-V tate the other link about its pivot.

6. An artificial limb including pivotally con.- nected shin and thigh sections, a linkage including a pair of links pivoted to each other and also to the shin and thigh sections respectively, one

, of said links consisting of two relatively slidable parts and a spring urging them into extended condition, and means controlled by the wearer' for compressing the spring and bringing the links approximately into a dead center condition.

7. An artificial limb including pivotally connected shin and thigh sections, a linkage including a pair of links pivoted to each other andi also to the shin and thigh sections respectively, one of said links consisting of two relatively slid- .able parts and a spring urging them into exvfor compressing the spring and bringing the links approximately into a dead center condition, said means including a iiexible member operable by the shoulders of the wearer.

9. An artificial limb including pivotally connected shin and thigh sections, a linkage includinga pair of links pivoted to each other and also to the shin and thigh sections respectively, one or" said links consisting of two relatively slidable parts and a spring urging them into extended condition, and means controlled by the wearer for compressing the spring and bringing the links approximately into a dead center condition, said means including a flexible member operable by the shoulders of the wearer, and a second flexible member extending about the pivot between the two links and connected to one part of the twopart link.

l0. An artificial limb including pivotally connected shin and thigh sections, a linkage including a pair of links pivoted to each other and also to the shin and thigh sections respectively, one of said links consisting of two relatively slidable parts and a spring urging them into extended condition, and means controlled by the wearer for compressing the spring and bringing the links approximately into a dead center condition, said means including a iexible member operable by the shoulders of the wearer, and a second flexible member extending about the pivot between the two links and connected to one part of the twopart link, and connected to the first ilexible of the shinsection relatively to the thigh' sectlon and means'for preventing relative movements o1 the members about their pivotal junction ,toi lock the shin section relativelyto (the thigh section, Y said last means acting by bringingfsaid members approximatelyinto a dead center c,ondition,and

adapted torbe controlled by-movements.of.the wearer. Y Y' l ISRAEL ALTERMAN. 

